This invention relates to a Stirling engine with a cylinder head which can be heated with a plurality of heating pipes bent in approximately U shape and with a cooler for the working gas.
Stirling engines are known in a number of forms; DE 4 016 238 C2 is here cited as an example, as a combination of such an engine with a boiler installation.
The basic principle of such a Stirling engine consists in that a constant volume of gas (helium is used mostly today) is forced to and fro within the Stirling engine by two pistons. On the one side the helium is heated in the heating pipes by the flame of a gas burner and the other side is cooled by a cooler. In between there is a regenerator, which extracts heat from the gas in its path from the hot side to the cold and feeds it back during the return flow. A gearbox connects the two piston so that power can be taken off, e.g. through generators. The pistons are moved alternately in parallel with or in opposition to one another, whereby the gas is compressed by the one piston and expanded again after the heat input by the other.
In addition to mechanical problems there is a perceived problem area on the one hand in optimizing the transfer of heat from the flame of the burner to the heating pipes and on the other hand in optimizing the cooler. A Stirling engine is known from DE 2 821 164 A1. The hot gas engine disclosed there is concerned not with the energy problems in the foreground here and this applies also to other solutions described in the state of the art. Thus for example DE 3 444 995 A1 shows a cyclone device with corresponding flow engines.
Furthermore, coolers are known from DE 4 232 555 A1 or for example from DE 4 401 247 A1 whose cooling bodies are provided with an outer, surrounding, helical groove traversed by the coolant. Such cooling bodies provided with a helical groove are comparatively expensive to make and in addition the coolant is always heating up as it passes through the helical groove, so that such cooling bodies cannot be optimally designed.